The Seventh-day Adventist church places an emphasis on healthy living, but Carson said he didn’t agree with a policy decision to vote against ordaining women.

“I don’t see any reason why women can’t be ordained,” he said.

Trump, however, said Carson’s faith is outside of the mainstream. He is Presbyterian and called his church “middle of the road,” while on Carson’s faith, he said, “I mean, Seventh-day Adventist, I don’t know about that.”

In response, Carson told The Associated Press that his faith is clear.

"There are a lot of people who have a close relationship with God, and you can generally tell who they are by the way they act, the way they treat other people," he said this week. "The reason that there are like 4,000 denominations is that people have looked at this and said, 'Let's interpret it this way. Let's interpret it this way.'

"Sometimes they get caught up in that and forget about the real purpose of Christian faith," he said.

On Trump’s criticism: "Donald Trump is Donald Trump. It doesn't surprise me that he's doing that. I would only be surprised if he didn't," Carson said. "There's a lot of things that are done in politics that are not fair, but when you get into the fray you have to expect those things."